LiTiO_(2)包覆对LiNi_(0.8) Co_(0.15) Al_(0.05) O_(2)正极材料的影响

Effect of LiTiO_(2) coating on LiNi_(0.8)Co_(0.15)Mn_(0.05)O_(2) cathode material

采用共沉淀法制备Ni_(0.8)Co_(0.15)Al_(0.05)(OH)_(2)三元前驱体,与LiOH·H_(2)O球磨混合后,通过高温固相法烧结制备LiNi_(0.8) Co_(0.15)Al_(0.05)O_(2)(NCA)正极材料,探究LiTiO_(2)包覆量(0、0.2%、0.5%、1.0%)对LiTiO_(2)包覆的Li(Ni_(0.8)Co_(0.15)Al_(0.05))1-xO_(2)正极材料性能的影响。通过XRD、SEM、透射电子显微镜(TEM)、电化学阻抗谱(EIS)及充放电测试等,分析材料的结构、形貌及电化学性能。LiTiO_(2)包覆在NCA材料表面,当包覆量为0.5%时,电化学性能最佳。在2.8~4.2 V充放电,1.0 C倍率的首次放电比容量达182.3 mAh/g,循环200次的容量保持率为76.4%;10.0 C倍率的放电比容量为141.3 mAh/g。

The Ni0.8Co0.15Al0.05(OH)2 ternary precursor was prepared by co-precipitation method, mixed with LiOH·H2O by ball milling, then sintered by high-temperature solid-phase method to prepare LiNi0.8Co0.15Al0.05O2(NCA) cathode material.The effects of LiTiO2 coating amount(0,0.2%,0.5% and 1.0%)on the performance of LiTiO2 coated Li(Ni0.8Co0.15Al0.05)1-xO2 cathode materials were investigated.The structure, morphology and electrochemical performance of the material were analyzed by XRD,SEM,transmission electron microscope(TEM),electrochemical impedance spectroscopy(EIS) and charge-discharge tests.LiTiO2 was coated on the surface of NCA material, the electrochemical performance was the best when the coating amount was 0.5%,when charged-discharged in 2.8-4.2 V,the initial specific discharge capacity was 182.3 mAh/g at 1.0 C rate, the capacity retention rate was 76.4% after 200 cycles;the specific discharge capacity was 141.3 mAh/g at 10.0 C rate.